Published on August 14, 2020
Liquid Biopsy Research for Breast Cancer
Dr. Daniel Stover of the Ohio State University Comprehensive Cancer Center shares information about his research on liquid biopsies and how it could impact breast cancer patients by monitoring treatment response. Watch as he discusses with metastatic breast cancer patient advocate Kelly Shanahan on how it could change long-term outcomes.
This is part two of a two-part series. Part 1: New PET Tracers for Breast Cancer.
Transcript | New Liquid Biopsy Tests for Breast Cancer
What is a liquid biopsy?
Liquid biopsy is a general or broad umbrella term that primarily refers to looking for cancer-related biomarkers from fluid from the body. Most of that tends to be from blood, although there are interest in liquid biopsy from urine or even spinal fluid. My lab primarily researches liquid biopsy from blood. And what we really focus on is circulating tumor DNA, which is DNA that's shed by both cancer cells and normal cells into the circulation and using very sensitive assays. We can actually detect the tumor DNA from a simple blood sample. And so for certain aspects or test that we attempt to do, we can get a very similar or complimentary information about mutations in the tumor from a simple blood test. And I believe that this really a lot of potential opportunity, particularly for our advanced cancer patients. We know that biopsies are painful and they can be risky.
They can cause a lot of anxiety. Sometimes we need them. When we need to look at protein receptors, we can't get that from the blood. So like estrogen receptor, progesterone receptor. But if we're looking for specific mutations, for example, a PI3-kinase mutation that might make a patient eligible for a novel therapy, that could be potentially detected by blood and avoid a biopsy. So I think that's a real benefit. And then the other thing is it's hard to get biopsies several times. Nobody wants to undergo a biopsy to begin with, and you certainly don't want two or three.
Whereas a blood test, a routine visit into the clinic, often you give two or three tubes of blood. So an additional tube of blood, every once in a while, might offer the ability to monitor over time. And so those are some of the things that my lab is particularly interested is can we develop tests that are cost-effective that we can monitor cancer over time, that we can identify new important biomarkers for patients that can guide therapy. And I think that there's a lot of potential, still a lot to learn, but we're excited about it.
How effective is a liquid biopsy?
Yeah. One of your projects that I've been involved with, I think it's brilliant. It's a trial to look at serial liquid biopsies and see whether you can determine whether a treatment is working within a couple of weeks of starting a new treatment.
We already know from some other work on liquid biopsies that it can detect progression earlier than imaging. We get imaging every three to six months often. Some of us are now on yearly, which is a little freaky, but can you tell us a little bit about this project, where you're integrating both liquid biopsies and imaging to determine whether you can tell rapidly whether a treatment's working? Because the worst thing is to be on a treatment, get a scan three months later to find out it's not working and you're like, "Dang, I wasted all that time."
Right. I think that that is a great point. And it's sort of I think aside from developing new effective agents, it's one of the sort of Holy grails in research for patients with advanced breast cancer. Both getting the right treatment to the right patient and then also changing it when you need to. Historically, and even now, some patients and providers follow tumor markers, but tumor markers don't work for every patient. And they're not reliable enough that our guidelines recommend them for all patients. In the same way in the last decade, circulating tumor cells or actual cancer cells that can be detected in blood have also been looked at. But neither of these have panned out to be able to tell us early enough to switch therapy that it impacts patients over the long term. So one of our goals is to use some of this new modern technology, these liquid biopsies using circulating tumor DNA, to say if we check the change in circulating tumor DNA at a week or two weeks or four weeks, can we distinguish whether it's working very early on.
And, as you said, and going back to our discussion about different PET scans, can we tie that in with earlier imaging and is liquid biopsy better? Is earlier imaging better? Are they better together? All these are questions that we don't know. But I agree with you, I think from a provider perspective and from a patient perspective, if we can tell that a patient is not responding to a new therapy within a couple of weeks, rather than waiting the 12 weeks that we routinely do to get scans, there's potential value in that. And so I think right now we're still in the early testing phase. And then the big hurdle will be to prove that it changes long-term outcomes. But I think that these are all new technologies. And I think that it's worth going back to that same important question because we still haven't solved it yet. And these may be part of a new answer.
Thank you for the research you're doing. Thank you for the tremendous care that you provide to your patients because I know people who see you as their oncologist. We need research. We need young, vibrant, exciting, smart researchers like Dr. Stover. We need people to participate in trials and we need more researchers like Dr. Stover who involve patients and advocates. I am going to go ahead and give everybody your Twitter handle. Dr. Stover is on Twitter. His Twitter handle is @Stoverlab, S-T-O-V-E-R-L-A-B. And I can't wait until we can go to conferences again in real life and I can give you a hug. So thank you so much for joining us today.
Thank you for the opportunity to join and thank you for being an important advocate on our studies. The questions that we ask are mostly questions that come from patients and because patients really are living it and can tell us what the important questions are to research. So thanks to you and thanks to all those watching today.